Lapping machine



April `15, 1941. H. s. INDGE LAPPING MACHINE .Filed Sept. 15, 1939 2 Sheets-Sheet l H5 H5551 715. f/VDGE www 2 Sheets-Sheet 2P Filed Sept. l5, 1939 Patente-d Apr. 15, 1941 UNITED STATES PATENT rFFICE LAPPIN G MACHINE Herbert S. Indge, Westboro, Mass., assigner to Norton Company, Worcester, Mass., a corpora- ,tion of Massachusetts Application September 15, 1939, Serial No. 295,093

10 Claims.

The invention relates to lapping machines;- and more particularly to a lapping machine for simultaneously lapping the opposed faces of a flat work piece.

One object of the invention is to provide a simple and thoroughly practical lapping machine for producing surfaces of extremely high quality. Another object of the invention is to provide a lapping machine having two opposed lapping elements which are arranged so that a substantially uniform surface speed of the lapping element may be obtained throughout the entire surface of the lapping element. Another object of the invention is to provide a lapping machine of the opposed lapping element type in which each lapping element is composed of a plurality of concentric rotatable lapping elements each of which is independently rotated. Another object of the invention is to provide a lapping machine with two opposed lapping elements each of which comprises a. plurality of concentric rotatable lapping wheels together with an independent driving mechanism for each of said concentric wheels which is arranged so that a substantially uniform surface speed may be obtained throughout the entire extent of each of said lapping elements. lOther objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. l is a vertical sectional view through the improved lapping machine, showing the arrangement of the opposed lapping elements together with the driving mechanism therefor;

Fig. 2 is a fragmentary plan view showing the mechanism for raising and lowering the upper lapping elements;

Fig. 3 is a fragmentary sectional view taken approximately on the line 3-3 of Fig. 1', showing the driving mechanism for the work carrying cage; and

Fig. 4 is a plan view of the lower lapping element.

The improved lapping machine has been illustrated in the drawings. comprising a base- I which supports a vertically extending column I I. The base III and the column II serve as supports is provided with a vertically extending sleeve I2 which rotatably supports a sleeve I3. The upper end of the sleeve I3 is provided with a driving plate I4 which supports an annular lapping ring I5 havingan upper plane lapping surface for abrading the work piece. The lower lapping element is preferably composed of a plurality of independently rotated lapping members Yall of which are provided with plane faces which are aligned to present a common plane lapping surface for abrading the under surface of the work piece to be lapped.

A rotatable sleeve I8 is supported within the sleeve I3 and is provided at its upper end with a driving plate I'l which serves as a support for a ring-shaped lapping wheel I8. In order to produce a break-up motion, thus breaking up the abrading lines produced by a plurality of concentric lapping elements, the lapping ring- Il is preferably provided with an inner aperture which is eccentric with its axisof rotation. The sleeve, I6 is provided with a pair of eccentrically mounted bearings I9 and 20 which serve to supporta vertical rotatable spindle 2| and are arranged to support the spindle 2|, with its axis eccentric to the axis of the rotatable sleeve I6. The upper end of the spindle 2| is provided with a driving plate 22 which supports an annular lapping ring 23 having an upper plane lapping surface. The three concentric lapping wheels I5. I8 and 23 are so arranged and mounted that their upper plane operative faces are aligned to coincide in a commonv plane to produce a lower plane lapping surface.

2|, when the spindle is rotated and its supporting sleeve IB is rotated, the lapping element 23 is moved not only in a rotary but also in a planevtary path, thus producing a relative transverse movement between the operative portions of the abrading surface, and thereby producing a breakup motion so as to eliminate the formation of scratches or markings-on the work surface.

In order to obtain a uniform lapping operation upon the surface of the work piece, it is desirable to .provide a substantially uniform surface speed at the inner and outer portions of the lapping surface. --In order to attain such a uniform surface speed of the lapping surface, the three concentric lapping wheels l5, I8 and 23'are preferably rotated at different speeds so that their surfaces travel at a substantially uniform surface speed.

The base III is provided with a driving mechafor two opposed lapping elements. The base I0 55 nism comprising an electric motor 30 which is Due to the eccentric mounting of the spindle provided with a V-grooved driving pulley 3|. The driving pulley 3| is connected by means of a V-belt 32 with a V-grooved pulley 33 which drives a Worm 34. The worm 34 meshes with a worm gear 35 which is keyed to a rotatable shaft 36. The shaft 36 is rotatably supported in a bearing 31 which is fxedly mounted within the machine base I and a bearing 38 which is flxedly supported on the column The worm 34 also meshes with a Worm gear 39 which is keyed to a rotatable shaft 40. The shaft 40 is rotatably journalled in a bearing 4| xedly mounted within the base I0 and a bearing 42 which is xedly mounted at the upper portion of the column Il.

The lower end of the shaft 36 is provided with a V-groove pulley 45 which is connected by a V- belt 46 with a V-grooved pulley 41 which is keyed to the lower end of the sleeve I3, whereby a rotary motion may be transmitted through the sleeve |3 to rotate the lapping wheel l5. The shaft 36 also supports at its lower end a larger diameter V-groove pulley 48 which is connected by means of a V-belt 49 with a V-grooved pulley 50 which is xedly keyed to the lower end of the spindle 2|. A pivotally mounted idler pulley l5| is provided to tension the belt 49 during the planetary movement of the lapping wheel spindle 2|. v

The lower end of the shaft 40 is provided with a V-groove pulley 53 which is connected by means of a V-belt 54 with 'a pulley 55 which is xedly keyed to the lower end of the rotatable sleeve |6 to impart a rotary motion to the lapping wheel |8. In the preferred construction it is desirable ,to increase the lapping' and break-up motion by rotating the intermediate lapping wheel |8 in the opposite direction from the lapping wheels and 23. The lapping and break-up motion is further increased by imparting a rotary and planetary movement to the wheel 23. This is preferably accomplished, as illustrated, by the worm and worm gear drive which is arranged to rotate the shaft 36 and the shaft 40 in opposite directions.

An upper opposed lapping element is provided to simultaneously engage and lap the upper surface of the work piece. The column is provided with a cylindrically shaped aperture 60 which serves as a support for a post or column 6| havlnga horizontally extending arm- 62 which serves as a rotatable support for a sleeve 63. The sleeve 63 supports afdriving plate 64 at its lower end which in turn carries a ring-shaped lapping element 6l. lThe sleeve 63 in turn serves as a rotatable support for a sleeve 66. The sleeve 66 is provided at its lower end with a driving plate 61 which supports a ring-shaped lapping element 68. The ring-shaped lapping element 68 is preferably formed with its inner aperture eccentric to its axis of rotation to facilitate the rotary and planetary movement of an inner wheel to be hereinafter described. The sleeve 66 serves a a support for a pair of spaced bearings 69 and 5x0. The bearings 69 and 10 rotatably support vertical spindle 1| which supports a driving plate 12 at its lower end. The plate 12 serves as a support for a ring-shaped lapping element 13. The three upper lapping elements 65, 68 and 13 are all arranged withplane lapping surfaces which are positioned to form a common plane-lapping surface to cooperate with the lower lapping elements to simultaneously lap the opposed faces of a plurality of flat work pieces.

The shafts 36 and 43 serve not only as driving mediums for the lower lapping elements but also are drivingly connected to rotate the upper lapping elements. The shaft 36 is provided at its upper end with a pulley 15 which is connected by means of a belt 16 with a pulley 11 4which is fixedly keyed to the upper end of th rotatable sleeve 66 to transmit a rotary movement to the lapping element 68. The shaft 46 is provided adjacent to its upper end with a pulley 18 which is connected by means of a belt 19 with a pulley 86 which is fixedly keyed to rotate the sleeve 63 and the lapping wheel 65 supported thereby.

The shaft 46 also supports at its upper end a pulley 8| which is connected by means of a belt 82 with a pulley 83 which is xedly mounted on the upper end of the spindle 1| which supports the lapping wheel 13. A pivotally mounted rotatable idler pulley 64 is provided to tension the driving belt 82 during the rotary and planetary movement of the lapping wheel spindle 1i.

To facilitatefloading of work pieces into the machine, the upperlapping wheels 65, 68 and 13 together with their supporting mechanisms are arranged to be moved toward and from the lower lapping element. The pulleys 15, 18 and 8| are preferably formed as wide faced pulleys to enable a continuous drive being imparted to the upper'lapping wheels during the approaching and receding movement of the same. The vertically movable column 6| is provided with a rack bar 96. To facilitate a vertical movement of the column 6|, a manually operable mechanism is provided comprising a hand wheel 9| which is mounted on the end of a rotatable shaft 92. The inner end of the shaft 92` is provided with a bevel vgear 93 which meshes with a bevel gear 94 supported on one end of a rotatable shaft 05 which is journalled in suitable bearings in the column The shaft also supports a worm 86 which meshes with worm gear 81. The worm gear 81 is mounted on one end of a rotatable shaft 95. The shaft. 95 carries a gear 96 which meshes with the rack bar 96. It will thus be readily apparent that a rotary movement of the manually operable wheel 9| serves through the rack and gear mechanism above described to move the column 6| and the upper lapping wheels together with their driving mechanism supported thereby vertically toward or from the lower lapping element to facilitate removal of finish ground work pieces and the insertion of new work pieces to be lapped.

A work carrying cage |00 is provided having al plurality of work receiving apertures |6| to support a plurality of work pieces between the opposed lapping elements, whereby the opposed faces of the work piece may be simultaneously lapped to a predetermined extent. The cage |00 1s given a combined rotating and gyrating movement, so that the work pieces are carried in an irregular path between the opposed lapping elements. The periphery of the cage |00 is formed as a spur gear which meshes with three symmetrically arranged gears |64, |05 and |06. E ach of the gears |04, |05 and |66 is keyed to a pin |61, |08 and |09, respectively. The pins |01, |68 and |09 are mounted eccentrically on the upper surface of a rotatable plate ||6 (only one of which has been shown in Fig. l). The plate ||0 extends beyond the periphery of the gear |04 and serves as a support for 'the cage |66 so that the cage rests on the three spaced plates ||0, preferably out of engagement with the lower lapping element. The plates |.|0 are mounted on the upper end of a rotatable shaft -gagement with the work pieces.

'| which is journalled in a bearing H2 formed in a portion of the frame which is iixedly mounted relative to the base I0.

In order to drive the cage |00, an electric motor H is mounted `within the base I0. The motor H5 is provided with a motor shaft H6 which supports a sprocket H1 at its outer end. The sprocket H1 is connected by means of: a driving chain H8 with a sprocket H9 mounted on a rotatable shaft |20. The inner end of the shaft is provided with a bevelled gear 2| which meshes with a bevelled gear |22 which is mounted on the lower end of the shaft Hl. Each of the shafts' H| is arranged so that it may be synchronously rotated so that the gears |04, |05 and |06 continuously mesh with the gear teeth |02 formed in the'periphery of the cage |00. In order to synchronously drive all of the gears |04, the shaft'ill is provided with a gear |23 which meshes with a large internal rotatable gear ring |25 which is yrotatably supported in a bearing surface |24 formed in a frame xed to the base l0. Each of the shafts H| sup porting the gears |04, 4|05 and |06 is provided at its lower end with gears |23 which mesh with the internal rotatable `ring gear |25. Itwill be apparent from the foregoing disclosure that when the shaft |20 is rotated to rotate the vertical shaft supporting the gear |04, a corresponding rotary and gyrating movement will be imparted to the gears |05 and |06, respectively, by means of the gear |23 and the rotatable internal ring gear |25. Due to the rotary and gyratlng movement of the gears |04, |05 and |06,.the work supporting cage |00 will be given a combined ro-t tary and planetary movement to carry the work pieces supported thereby through an irregular path between theopposed lapping elements above l described.

The operation of this improved lapping machine will be readily'apparent from the foregoing disclosure. Assuming the parts to be in the positionv illustrated in Fig. 1, a plurality of work pieces are placed in the plurality of apertures |0| in the cage |00, and the motors 30 and H5 are then started to rotate and gyrate thecage |00 and to impart a rotary movement to the lower lapping wheels I5, i8 and. 23 and also to the upper lapping Wheels 65, 66 and 13. The manually operable wheel 3| is then rotated to lower the column 6| and the head 62 to move the upper lapping elements composed of the lapping wheels 65, 66 and i3` into operative lapping en- The lapping operation may then be continued to lap the opposed faces of the work piece to the desired extent so as to produce a highly refined lap surface thereon. After la lapping operation has been completed, the manually operable lwheel 0| is rotated to again raise the column 6|, the head 62 and the upper lapping elements-comprising the lapping wheels 65, 68 and 13 to an upper inoperative position to facilitate removal of the lapped pieces of work and insertion of new work pieces thereinstead. y

It will thus beseen thatthere has been provided by this invention apparatus in which the various object-s .hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forthi or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:l

1. In a lapping machine, a pair of opposed lapping elements. each of said lapping elements comprising a plurality of concentric independently rotated lapping wheels, means independently to rotate each of said wheels, a work supporting cage between said elements having va plurality of work receiving apertures formed therein, means to impart a planetary movement to. at least one of said lapping wheels, and a driving mechanism for said cage to rotate and gyrate said cage to carry a plurality of work pieces through an irregular path between the operative faces of said lapping elements.

2. In a lapping machine, a pair of opposed lapping elements each having a substantially plane operativeface, each of said lapping elements comprising a plurality of concentric rotatable lapping wheels, means independently torotate each oi' said wheels at different speeds whereby a substantially uniform surface speed may be obtained throughout the extent of the operative face of each of said lapping elements, means to impart a planetary movement to at least one of said lapping wheels of each element. a work cage between said elements having va plurality of work receiving apertures therein, and

means to rotate and gyrate said cage simultaneously to carry a plurality of Work pieces through an irregular path between-the operative faces of said lapping elements.

3. In a lapping machine, a pair of opposed lapping elements each having a substantially plane f operative face, each of said lapping elements comy to impart a planetary movement to at prising three substantially concentricrotatable lapping wheels, means to rotate the outer and inner' wheels of each element in the same direction, means to rotate the intermediate wheel of each element in the opposite direction therefrom, and means to impart a planetary moyement to the inner vwheelu of each element.

4. In a lapping machine, a pair of opposed lapping elements each having a substantially plane operative face, each of said elements comprising three substantially concentric rotatable lapping wheels, means to rotate the outer and inner wheels of each element in the same direction, means to rotate the intermediate wheel of each element in the opposite direction from the adjacent outer and inner wheels, and means to impart a planetary movement to the inner wheel of each element, said opposed lapping elements having their respective wheels rotating in opposite directions.

5. In a lapping machine, a pair of opposed lapping "elements each having a substantially plane operative face, each of said lapping elements comprising a plurality of concentric rotatablelapping Wheels, means independently to rotate each of said wheels, and means to impart a planetary movement to at least one of the wheels of each lapping element. i

6. In a lapping machine, a pair of opposed rotatable lapping elements each having a substantially pl-ane operative face, a work carrying cage` having a plurality of work receiving apertures 1ocated between said elements, means to impart a rotary and gyrating movement to said cage, one of said elements at least comprising a plurality of concentric rotatable lapping wheels, mears independently to rotate each of said wheels, and means least one of said wheels.

7. Ina lapping machine, a pair of opposed lapping elements each having a substantially plane operative face, each of said lapping elements comprising three substantially concentric rotatable lapping wheels, means to rotate the outer and inner wheels of each element in the same direction, means to rotate the intermediate wheel of each element in the opposite direction therefrom, means to impart a planetary movement to the inner wheel of each element, a work cage between said elements having a plurality of work receiving apertures therein, and a driving mechanism for said cage to rotate and gyrate said cage simultaneously to carry a plurality of work pieces through an irregular path between the operative faces of said lapping elements.

8. In a. lapping machine, a pair of opposed lapping elements each having a substantially plane operative face, at least one of said lapping elements comprising a plurality of substantially iconcentric rotatable lapping wheels, means independently to rotate all of said lapping wheels, and means to impart a planetary movement to at least one of said lapping wheels.

9. In a lapping machine, a pair of opposed 1ap ping elements each having a substantially plane operative face, at least one of said elements comprising a plurality of substantially concentric rotatable lapping wheels, means independently to rotate all of said lapping wheels, and means to impart a planetary movement to the inner lapping wheel. n

10. In a lapping machine, a pair of opposed lapping elements each having a substantially `plane operative face, each of said lapping elements comprising a plurality of substantially concentric rotatable lapping wheels, means independently to rotate all of said lapping wheels, and

means to impart a planetary movement to at least one of the lapping wheels of each element.

HERBERT S. INDGE. 

